High-pressure gas-filling apparatus and method

ABSTRACT

A high-pressure gas-filling apparatus and method for filling gas containers such as lamps to a positive pressure of several atmospheres to minimize waste of supply gas. Empty lamp bodies are attached to a filling manifold and the filling apparatus is evacuated to a desired pressure range before filling occurs. After the lamps have been filled and sealed, control valves are closed to trap unused supply gas in the system. The trapped gas is then liquified and collected in a freezeout chamber by applying cooling to the freezeout chamber. When cooling is discontinued, the liquified gas in the chamber revaporizes and when sufficient pressure builds up, the gas reenters the highpressure supply side of the apparatus for reuse. Through the use of the freezeout chamber one of the supply containers can be purged, when its pressure will not operate a regulator, and the residual gas therein be placed into the other supply container.

United States Patent [72] Inventor Teddy J. Peacher Huntsville, Ala.[21] Appl. No. 838,117 [22] Filed July 1, 1969 [45] Patented May 4, 1971[73] Assignee the United States of America as represented by theSecretary of the Army [54] HIGH-PRESSURE GAS-FILLING APPARATUS ANDMETHOD 4 Claims, 1 Drawing Fig.

[52] US. Cl 53/12, 53/79, 316/20, 316/30 [51 Int. Cl B65b 31/00 [50]FieldotSearch 53/7,12, 22, 86, 88,112, 79; 316/20, 30

[56] References Cited UNITED STATES PATENTS 2,768,488 10/1956 Shelnutt53/1 12 2,963,834 12/1960 Stanley et a1. 53/88X Primary Examiner-TravisS. McGehee AttorneysHarry M. Saragovitz, Edward J. Kelly, Herbert Berland Charles R. Carter ABSTRACT: A high-pressure gas-filling apparatusand method for filling gas containers such as lamps toa positivepressure of several atmospheres to minimize waste of supply gas. Emptylamp bodies are attached to a filling manifold and the filling apparatusis evacuated to a desired pressure range before filling occurs. Afterthe lamps have been filled and sealed, control valves are closed to trapunused supply gas in the system. The trapped gas is then liquified andcollected in a freezeout chamber by applying cooling to the freezeoutchamber. When cooling is discontinued, the liquified gas in the chamberrevaporizes and when sufficient pressure builds up, the gas reenters thehigh-pressure supply side of the apparatus for reuse. Through the use ofthe freezeout chamber one of the supply containers can be purged, whenits pressure will not operate a regulator, and the residual gas thereinbe placed into the other supply container.

I7 29 '25 =ir= 5 Q E 5 E PRESSURE REGULATOR VACUUM PUMP PATENTED HAY 4mINVENTOR Teddy J. Peocher,

BACKGROUND OF THE INVENTION This invention relates to the field ofhigh-pressure filling of containers such as lamps. In present systemsused for filling gas short are lamps to positive pressures of severalatmospheres, the systems are pumped down by a vacuum pump to a desiredlevel. A vacuum valve is closed and the regulator opened to allow gas tofill the lamps. After the lamps have been filled, sealed, and removedfrom the filling manifold, the gas remaining in the system is allowed toescape before another vacuum is pulled on the system. The gas supplycontainer cannot be exhausted; it must be considered empty when itsinternal pressure drops below 10 atmospheres, even though there is 20percent or more of the gas remaining which is wasted. The high cost ofgas such as zenon, neon, and argon, for example, makes this situationundesirable.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWING The singleFIGURE shown in the drawing is a schematic of the gas filling apparatus.

PREFERRED EMBODIMENTS OF THE INVENTION A group of containers such aslamp bodies A to be filled are attached to a filling manifold 1 that isconnected to gas supply containers 3, 5, and other elements to bedescribed later by conduits of tubing. The supply containers containgas, such as zenon under 500 p.s.i.g. internal pressure and have theirrespective valves 3a, 5a closed. Control valves 7, 9, ll, l3, l5,

and 17 are opened. A gas pressure regulator 19 is opened and vacuum pump21 is started to pump the system down to mm. mercury pressureascertained by vacuum gage 23. At this pressure, valves 9, ll, 13, andare closed as well as regulator 19. Supply container valve 3a is opened(or valve 5a if container 5 is to be evacuated) pressurizing ahigh-pressure manifold 25. A valve in regulator 19 is opened to regulatethe pressure for filling the lamps as determined by a pressure gage 27.After the lamps are filled, valve 7 is closed;' the lamps are sealed bya known cold weld process, such as pinching off the lamp fill tube, andthe lamps are removed from the manifold. Valve 11 is then opened and gasremaining in the filling system is now trapped between valves 7, 9, l3,and 15 as well as check valve 29. and pop-off valve 31. This trapped gasis not liquified and collects in the bottom of collecting means orfreezeout chamber 33 by applying a cooling system 35 to the chamber.This cooling system may be a Dewar flask of liquid N or other suitablecoolant, or a mechanical refrigeration unit. Valve 11 is then closed andthe cooling to the freezeout chamber is discontinued. As the gasrevaporizes and the pressure builds up to greater than that in the highpressure manifold, it will reenter the high-pressure manifold throughcheck valve 29, which prevents backflow to 500 p.s.i. and open valve 17.A pressure gage records the pressure in the high-pressure manifoldconnected with the supply containers.

A second group of lamp bodies are mounted on the filling .manifold forfilling. Valves 9 and 13 are opened and the system below valves 7 and 11is pumped down to 10 mm. mercury pressure by the vacuum pump and thelamp filling cycle explained above is repeated.

The above filling procedure is repeated until the pressure in the gassupply container drops below that required to operate regulator 19 atthe required filling pressure. When two supply containers are utilized,one can be used until its pressure is too low to operate the regulator,then the other container can b switched in.

Assuming that both containers have been used down to the minimumpressure for reliable system operation, container 3 can be purged andthe residual gas therein placed into container 5. Valves 3a and 15 areopened and the cooling system is applied to the freezeout chamber untilthe pressure in supply container 3 falls within the range of 5-10p.s.i.g. (amount required to be left in the container by the gassupplier) at which time valve 3a is closed and valve 50 is opened andthe cooling to the freezeout chamber is discontinued. When all the gashas vaporized, valves 5a and 17 are closed and cooling is again placedon freezeout chamber 33 until all the gas in high-pressure manifold 25is liquified at which time valve 15 is closed. At this point, it isnoted that the cooling system must be kept on the freezeout chamberuntil the empty container is replaced and the filling system, other thanthe freezeout chamber, is pumped down. Valves 5a and 1 7 are opened andthe cooling to the freezeout chamber is discontinued. Regulator 19 isclosed and as the gas revaporizes, the pressure builds up; it willreenter the high-pressure manifold through valve 17 and into supplycontainer 5.

Other gases such as neon and argon, for'example, can be used as thefilling gas by varying the cooling technique from a bath of liquidnitrogen to another suitable coolant or mechanical cooling cycle.

Moderate and low-pressure containers may also be filled with the fillingapparatus by varying the filling pressure of the gas.

I claim:

I. An apparatus for filling containers such as gas lamps to a positivepressure of several atmospheres comprising: a gas supply; a fillingmanifold and means for regulating the gas pressure therein disposed incommunication between the lamps and said gas supply; means disposed incommunication with said manifold and said gas supply for collecting andstoring residual supply gases therefrom and for returning said gases tosaid supply; and means for cooling the residual gases.

2. An apparatus as set forth in claim 1 further comprising ahigh-pressure manifold disposed in communication between said gas supplyand said regulating means.

3. An apparatus as set forth in claim 2 further comprising a vacuum pumpfor pulling a vacuum on the apparatus.

4. A method of filling gas lamps to a positive pressure of severalatmospheres comprising: connecting lamps bodies to a filling manifold;evacuating the filling manifold; regulating the gas pressure from asupply to the filling manifold; and collecting the residual gases fromsaid manifold into a collecting means after the lamps have been filledand sealed for return to the supply, said collecting performed byapplying cooling to said collecting means.

2. An apparatus as set forth in claim 1 further comprising ahigh-pressure manifold disposed in communication between said gas supplyand said regulating means.
 3. An apparatus as set forth in claim 2further comprising a vacuum pump for pulling a vacuum on the apparatus.4. A method of filling gas lamps to a positive pressure of severalatmospheres comprising: connecting lamps bodies to a filling manifold;evacuating the filling manifold; regulating the gas pressure from asupply to the filling manifold; and collecting the residual gases fromsaid manifold into a collecting means after the lamps have been filledand sealed for return to the supply, said collecting performed byapplying cooling to said collecting means.